Perhaps you should try some spelling variations:
thieu xanh » chieu xanh, hieu manh, thien anh
hoc thieu » toc thieu, hoc hien
thang cua » thong cua, hang cua, than cua
trung cua » truong cua, trung tuan, trung cap
cong dan » cong tan, huong dan, cong dong
cong san » cong tac
toan cau » toan cao, toan ban, toan tap

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: hoc thieu xanh - hanh ((thang cua) or (trung cua)) nhung ((cong dan) OR (cong san)) toan cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc thieu xanh - hanh ((thang cua) OR (trung cua)) nhung ((cong dan) OR (cong san)) toan cau.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc thieu xanh - hanh ((thang cua) or (trung cua)) nhung ((cong dan) OR (cong san)) toan cau".
• Adding a wildcard symbol may retrieve word variants: hoc thieu xanh - hanh ((thang cua) or (trung cua)) nhung ((cong dan) OR (cong san)) toan cau*.